CVE-2021-31873 json
An issue was discovered in klibc before 2.0.9.
published 5y ago modified 4mo ago also EUVD-2021-18748
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.2%
- EPSS 2.2% chance of exploitation in 30 days, percentile 82%
- public exploits
- 0
- none known
Summary
An issue was discovered in klibc before 2.0.9. Additions in the malloc() function may result in an integer overflow and a subsequent heap buffer overflow.
Patch / fix
- klibc_project klibc 2.0.9
- klibc Debian 14, Debian 13, Debian 12 2.0.8-6
debian advisories DEBIAN-CVE-2021-31873
- klibc Ubuntu 18.04 LTS 2.0.4-9ubuntu2.1
- klibc Ubuntu 20.04 LTS 2.0.7-1ubuntu5.1
- klibc Ubuntu Pro 14.04 LTS 2.0.3-0ubuntu1.14.04.3+esm2
- klibc Ubuntu Pro 16.04 LTS 2.0.4-8ubuntu1.16.04.4+esm1
ubuntu advisories UBUNTU-CVE-2021-31873
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- klibc Alpine 3.24, Alpine 3.23, Alpine 3.22 +3 more 2.0.9-r0
alpine advisories ALPINE-CVE-2021-31873
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
Is CVE-2021-31873 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
2.17% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-190 Integer Overflow or Wraparound
References
-
git.kernel.org
/pub/scm/libs/klibc/klibc.git/commit/?id=a31ae8c508fc8d1bca4f57e9f9f88127572d5202
patch, third-party-advisory
- github.com /huolinjue/klibc/commit/a31ae8c508fc8d1bca4f57e9f9f88127572d5202
-
kernel.org
/pub/linux/libs/klibc/2.0/
release-notes, third-party-advisory
-
lists.zytor.com
/archives/klibc/2021-April/004593.html
mailing-list, release-notes, third-party-advisory
-
openwall.com
/lists/oss-security/2021/04/30/1
mailing-list, release-notes, third-party-advisory
-
lists.debian.org
/debian-lts-announce/2021/06/msg00025.html
mailing-list, third-party-advisory
Sources
- CVE List CVE-2021-31873
- NVD CVE-2021-31873
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.